Just This Once
by Aurumsky
Summary: A war was never something Mavis wished for. Neither was having Zeref as an enemy or sitting in the guild library thinking how she can maybe stop the war. With Zeref. Yet that is exactly what she is doing right now.
1. Chapter 1

**This** **story was inspired by a phrase "Just this once, everybody lives" from Doctor Who, and is something I've been trying to wrap my head around for quite a while and t** **here will be another chapter coming sometime soon.**

 **I hope you like it and please review.**

* * *

After the great Trade war, Fiore had been in peace with all its neighboring counties, and Mavis had preferred for it to be that way.

War with the Alvarez empire had never seemed possible to her.

Until it happened.

Mavis had never expected for Zeref to try to take Fairy Heart with a plan so... grand.

A war.

Mavis despised wars. Hated them with her whole being. And Zeref knew she did. He knew, she was sure he did. There was no other reason he would attack Fiore with an army of over thousands of soldiers.

She knew Zeref wanted her body. It was a lacrima with limitless magic power after all. But, some days, she liked to think, that Zeref wanted it for other reasons. Some days, she even let herself to blush at the images her mind produced.

In the guildhall of Fairy Tail, she shook her head. She was in the middle of the war. There was no time to think of 'what if's.

Glancing at her guild, rather who still were inside of it, Mavis stopped pacing. Makarov caught her eyes, and the weariness and worry he held in them, made Mavis' emotions whirl from regret to love and back to regret.

There must be something she can do. Her plan C, the one she had relied the most on, had been left unused, since Cana had made her way to the battlefield after Mirajane's call.

Mavis clenched her fists.

Her children were in danger, and all she can do is pace around the guildhall thinking of 'what if's. She relaxed her hands.

This war had gone long enough.

And there was only one aside from her who could stop it.

She found him in a ship, sitting alone in front of a map of Magnolia. He was leaning forward, a tiny scowl on his face, a hand running in his hair as the other tapped against his thigh.

Apart from the scowl and slightly different clothing, he looked exactly how Mavis remembered him. Black, oddly shaped hair, black eyes that Mavis had once loved to look at, childish face, yet a look that carries so much sorrow, a lean body and narrow shoulders.

When she took a step forward from her place on the other side of the long table, his head jerked up, like he could sense her. Mavis' lips tugged up. His eyes had widened a fraction in shock, but he never changed to defensive.

"This war must end, Zeref." She spoke with gentle voice, like she had spoke to Makarov and Zera more than once. His black eyes moved from corner to other, as if in search for her.

"Mavis?"

The sound of his voice made her heart clench. It held little to no emotion, but the undertone was hopeful. She hadn't even dared to dream that he would hope to see her. If he did. But well, he had many reasons to wish to see her, to be able to touch her so he could maybe pierce her heart or rip out her organs or just kill without even touching-

"Zeref, retreat your troops and leave my city."

"You're here, right, Mavis. I know you're here."

"You are on the losing side, Zeref. _Leave_." A lie. As if his troops would be losing. Heck, Fairy Tail might end up losing this war, but Mavis liked to think they were equals.

"I need your help."

Mavis closed her mouth that had been left open at his last comment. He needed her. Her face set into a frown, he never needed anyone.

Zeref waited, looked straight to where Mavis was standing, his eyes looking through her, and it was unsettling for Mavis. She wasn't used to people who knew she was there, exactly where she was standing and where her eyes were, but couldn't see her. Then he sighed and looked back to his map.

Mavis moved forward, around the table to him, took a look of the map, then at his face, his eyes, circled him and took in his clothes. She waved a hand in front of his face, poked his shoulder and went right through and sat on the table, on the edge of the map. Zeref gave no sign he could sense her anymore.

So she left.

* * *

Mavis visited him twice the next day, at the morning, when he had just woken up and aside from yawning every now and then, looked just like he had the day before. She sat on the table, across the map he had changed onto a different one, a more detailed, probably newer map that he had made many different markings to several places Mavis never bothered to read. They were old, she had no use for them. She tried talking to him, convincing him to leave, but he was too absorbed in his job to show if he had noticed her. It hurt Mavis, to be honest.

Mavis sat for three hours, just watching him, hoping he could see her so she could have a conversation with him. She _needed_ to have a conversation with him.

She left when his white haired comrade knocked on the door and it creaked open.

The next time she visited was at night, when she knew that without the war, the city would be asleep, aside from maybe a small amount of people who would be partying. It angered Mavis it was her that had taken away the normal life of the people in her city.

Zeref was still awake, although barely. Unlike the two other times, now he had no map. Mavis stayed at the door, watching as he scribbled on a notebook, turned pages and read something, sighed, yawned, rubbed his eyes and squinted before resuming writing.

In the light of the orange fire, he looked so much older than normal.

She didn't want to know what he was doing. Whatever it may be, at this point she didn't care anymore.

Plan A is a failure, she should move on, decide what is the best source of action now.

Yet, she ended up spending the whole night watching as he wrote down details into his notebook.

* * *

Mavis needed a plan. She needed something that fulfilled all her needs. No war, no deaths, her death, preferably so that Zeref dies too.

Only thing she can think of is a spell.

A spell. No vaporizing the enemy or turning back the time, she would never be able to accomplish that. Resetting time, possible, depending on how much of it she will reset.

Mavis would have had Cana destroy Fairy Heart and free her body so that she could go on with her plan C, but this is even better. All she needs to do is cast a spell, and everything is peaceful again, no war, no deaths, except hers and Zeref's.

Maybe she can even do it so that she and Zeref will be transported to another country that is away of Fiore and Alvarez and they can live to-

Except Zeref cannot see her and her magic power isn't enough to cast such a spell alone.

Heck, her current magic power isn't capable of anything but a simple, small, _amateur_ illusion. All her power residents in Fairy Heart, and no one will ever let her cast the spell if they knew, no less in the guild, and she has absolutely no way of getting it out herself.

She needs someone that has both enough magic power and is also capable of moving Fairy Heart out of the guild's basement.

Sitting on the nearest table in the guild's library, Mavis set on work, scribbling a very detail lacking spell, but for now, she had something to work on.

She needed Zeref.

* * *

Getting Zeref would probably be the biggest problems in her plan. She and Zeref were in no way friends, let alone on the same side.

They were in a war, and Mavis was most likely betraying everyone who was battling against Alvarez empire as she read the spell she had been creating for two days over and over in her mind while thinking of ways to convince Zeref to help her.

Right now, she didn't care. The war has to end, and she is holding the best way on her hands.

Mavis bit her lip.

She didn't have too much time on her hands before the Spriggan Twelve would be in the guild.

She needed Zeref _right now._

* * *

He stood in front of her, this time _really_ looking into her eyes, this time _seeing her_. Which was ridiculous because no way would Zeref be able to see _her_.

Yet there he was, looking into her eyes, watching as she waved a hand in from of him and blinking when she snapped her fingers in front of his eyes.

Mavis huffed, crossed her arms and looked up at him.

"How come you can see me?"

Zeref said nothing as he raised his hands to his chest, delicate fingers working on the fabric of his clothes.

Mavis pursed her lips, watching as he slowly removed first his toga, then his robes, and let her eyes wander when his chest was bare. He had muscles, though she knew that already, it was the first thing she had learned of him.

She swallowed her enraged shout.

On his chest, above his heart, was the mark of Fairy Tail. She ground her teeth together, balled her fists and bit back a growl.

It would have been fine otherwise. A tattoo was removable. But this one. This one had been engraved to his flesh and skin.

It still looked new to Mavis. Two, three days perhaps, it was red around the edges, made with a sharp object with a steady hand, poorly healed, most possibly infected. It would scar, never go away, even upon his death, if he ever died. Even after other four hundred years, he would carry the mark, nevertheless was Fairy Tail still existing or not at that time.

It was on other level of commitment. Mavis knew, that when he was young, three, four hundred years ago, guilds still did that, crave their marks on its members' flesh, so that even if they left, they would never get fully away from the guild, but carry the mark forever with them, bringing shame, or honor, depending on the guild.

"Why?"

Mavis hated the taste of salt that she felt on the tip of her tongue when she spoke. She hated the slight waver, angry or not, in her voice.

"Because I needed to see you."

Mavis hadn't thought he would be able to see her after that. Joining a guild was more than getting its mark on skin. He _shouldn't_ be able to see her. He was, in no way, an official member Fairy Tail had accepted.

She didn't say it, however.

"You didn't need to see me when I came to talk to you after Tenrou."

"I need to now."

Mavis knew he did. _Of course_ he did. Anyone could see that when their arch enemy would engrave someone else's guild mark on their flesh. If it wasn't a joke.

But Zeref didn't joke. He didn't have a sense of humor, not even a bad one.

"Why?"

Zeref smiled sadly.

"There is so much death, but so little is accomplished. I think I have grown bored of this game of ours."

Mavis grit her teeth. "This was never _our_ game, Zeref. This is your cruel game I am forced to watch play, and do my best at stopping it."

"But Mavis," Zeref raised his chin, tilting his head "we have played this game since your death. I sincerely think it was you that was the one who initiated the first move."

Mavis glared at him, poured all the hate she felt for him into the glare, then raised her head, rolled her shoulders and said, "Are you willing to discuss with me about the plans to stop this war?"

It was no surprise to her that Zeref accepted her offer.

He said it himself. He is tired.

* * *

"Your objective is to obtain Fairy Heart. And mine is to stop you from doing that." Mavis had never had such a serious conversation with Zeref. She had never wanted to, but now, she had to. It was a matter of pride.

"Neither of us is ready to retreat, so I have an offer to you. Last night, I made a spell. It's nowhere near safe and it maybe won't work, but it is the best I could come up with. To complete and perform it, I will need your help and magic power."

Zeref's brows rose slightly, he didn't ask a thing, let Mavis talk, and of that she was thankful. She wouldn't be able to answer to anything he asked, of that she was certain.

"Majorly, the spell is meant to reset time, but not to turn it back. All in all, if the spell succeeds, the war will have never happened, and no one beside me and you will be able to remember it, if we survive."

She kept a pause, looked at his face and drew in a calming breath. "Now, I have no experience with Time Magic aside from Fairy Sphere, but then I used the members' magic, not mine, and the spell uses up most of your magic power. I trust that you are capable of casting it."

Zeref didn't move, only looked into her eyes with a look that was uncertain, but mostly unconvinced. "Where do you plan on obtaining such a high amount of magic?"

Mavis tensed. The part of the plan she was most uncertain of. It was part of the plan, a big part, but Zeref may not accept it. "To get my hands on a great amount of magic power, I will have to use Fairy Heart as my source. That means, it will be destroyed."

His eyes flashed with something that would have been anger.

"No."

"Zeref, you have to agree, I have thought about this for days, and it's the only way I could think of that we can save everyone."

He looked straight into her eyes, his black ones unwavering. Then he sighed.

"Look, Mavis," Zeref said, annoyance creeping into his voice, only a bit, but still detectable, "I trust in your plan,if it works exactly like it should, great. But the problem here is that it might not kill me, but it will kill you."

Mavis refused to say that she was already dead. He knew it, just forgot. That she had been dead for over eighty years and still hadn't moved on. His love for her wouldn't change anything, no matter how much she wished for it.

"Are you afraid of death, Zeref?"

He froze mid motion in wiping hair from his eyes. Then he chuckled dryly, turning guilty eyes to see her.

"Perhaps I am." He whispered.

Mavis bit back he cruel words. Zeref had taken away her chance to become an adult, he had taken away her possibility to see her guild grow up, to start a family, to love anyone else beside him, and oh, how she till despised him for it.

Yet, her heart broke every day on the behalf of the man who she had named her enemy. And she knew, that still, somewhere in her heart, afraid to be freed, she cared for him more than Fairy Tail.

"Then you will live." She said. He will, she would make sure of that.

"But then you will die."

Mavis pursed her lips. "That is not the problem here. I already am dead. Destroying my body, would only mean I can finally die properly."

Zeref looked at her into eyes, and she swore he was sad. The thought brought tears to her eyes. "But then what reason do I have to stay alive, if you're not there?"

And Mavis let the tears fall free.


	2. Chapter 2

She decided, she needs more time. Mavis had probably cried two days after hearing why Zeref would not agree to her plan. The spell needed more adjusting, more small details she had overlooked previously.

Time magic was hard. It was a Lost Magic after all. But combining it with Teleportation Magic and tiny bit Memory Magic, it would be easier.

Mavis pushed aside the books she had used for researching Space Magic, it was no use. The problem was, she was not interested in turning the time back, but making it so, that she will never have died and… Maybe it would be better if she died. If Grimoire Heart was never created, the time would be rewritten on its own, the core members would have been able to hold the trials and never disappear… But would Zeref interfere then? Was Fairy Heart something that needed to be created? Mavis hoped not.

No, she would only need to make it so that the war will never happen. _What_ was it that made Zeref lead a war?

Fairy Heart alone? Mavis didn't think so. There had to be an excuse, something he could blame Magnolia on and use it to start a war. But what if there wasn't?

She didn't know.

Mavis didn't know and she hated not knowing. She could not ask from Zeref. he wouldn't tell her. What is she missing? Something that set the whole chain of events to start. _What was it?_

Mavis leaned on her elbows. She really shouldn't be locking herself in the guild's library thinking of how she can maybe erase the war.

What even happened to her before she died?

Zera, Yuri, Precht, Warrod, magic, Zeref, magic, founding guild. Death. How did she die?

Mavis wrote it down, the names and everything she remembered. Zeref taught her magic, that she remembered. She casted Law and stopped aging, she remembered that, too. So how did she die?

A sudden realization hit her like a bucket of ice cold water. Zeref. The kiss.

Of course.

The kiss. Falling in love.

She just didn't need to die. But leading Fairy Tail to believe so just in case they would wish to look for her body. She would need to cast an illusion. But illusions didn't work well with Teleportation Magic, and _that_ was way too necessary.

She would manage. She always did.

Mavis smiled to herself as she wrote down the details, then victoriously gazed down on the parchment of paper that was full of messily scribbled notes and additions to the original spell.

She can do it.

For her family.

* * *

"Please Zeref. Just this once."

Zeref paused at his pacing.

"Don't you see, Mavis? If you just hand over Fairy Heart, everything will be easier."

Mavis shook her head. Fairy Heart was precious to her, it had protected her family for decades, and she wouldn't let it get destroyed, only for the war to break out again.

"No, Zeref. My family is there fighting to _protect me._ They have for weeks now! I can't go to them now and say that I'm giving up!"

Zeref scowled. The expression was foreign on his face, and Mavis felt the urge to smooth his face down again. She quickly pressed the feeling down.

She didn't love him anymore.

She didn't.

The scenery around them changed. They were no longer on the field, but sitting in a tree that grew on the border of it, Mavis on a slightly lower branch than Zeref.

"Zeref, I have the spell. I only need you to complete it."

"Why not ask someone from Fairy Tail?"

Mavis laughed quietly. "Do you think they would let me do that? Sacrifice my body they have fought to protect for this long?"

Zeref's scowl deepened. "I suppose not."

"Please Zeref, just this once."

He was silent, gazing down form the tree they had settled at, his right hand picking at the deep brown bark while the left was playing with his white toga. At times, his lips would quirk up a bit, then again settle into their naturally sad line.

Mavis kept playing the line in her head, smiling sadly at it. _Just this once._ They wouldn't have another try, they wouldn't live to see if they succeeded. It was sad. While she was watching Zeref, she realized, even after the hundred years she had been alive, she wasn't ready to leave the world behind her.

As Zeref's expression softened, Mavis knew she had won him over.

"Fine," Zeref sighed finally, not looking at Mavis. "Just this once."

* * *

Getting the Fairy Heart was easy. Zeref worked his magic on it from outside of the guild while Mavis masked their presence and replaced the lacrima with a thought projection.

It wouldn't fool everyone. Hell, Mavis was pretty sure it would fool only Asuka, but once it was gone, no one would be fast enough to to find their location before they would cast the spell.

The guild knew something was going on. Mavis was gone much, so she wasn't very updated on their trust situation, but she could see it when she saw her mages, their eyes, specifically. The look they gave her now wasn't as trusting as it had been a week ago.

At the moment, Mavis shouldn't care. She did, despite of what she told herself.

Finishing the spell was harder.

She could no longer use the library, because it had been burned by one of the attacks, and she didn't actually have a home where she could curl up and peacefully work on it. The local library wouldn't have been of any use even if it hand't been destroyed weeks ago. The only thing Mavis knew to do was to sneak in Levy's apartment after she had gotten past the protective rune barrier around the building, and then the little mage's apartment.

To be honest, Mavis rather liked to do it. But she still felt horrible.

Mavis wasn't exactly a genius, though smart, and Zeref had only agreed to cast it, not write it. The amount if magic types combined, the magic power it needed so it can be casted, being able to focus on all the things she was going to fix... It wasn't going to be easy.

Yet, she had to do it.

* * *

They were standing on a small hill, overlooking the field that was currently used for a battle. Mavis could identify Wendy, Lisanna, Gray... Almost everyone from Fairy Tail and other guilds, battling their way through the mass of soldiers. She wished she would have been able to give them all a big hug and a kiss on the cheek and a huge smile, because the pain she was feeling now would be easier to bear.

She smiled sadly, warm tears falling from her eyes.

Really, a huge group hug with them all would have been nice. And a speech from the Third, and she knew she was being greedy right now. Mavis' smile slowly died down, yesterday, in the guild, there had been no one. No one to talk with, say a couple words that didn't include the war. If she would have been able to wish that one person good luck, to see them smiling. Smiling, not battling, injured, pushing themselves one step further.

In a way, it warmed her heart. She would see them at their bravest. When something else than joy drove them forward. Wish to live to see another day, need to protect their homeland, family, her.

Her walls crumbled down. The guilt she had kept at bay came with overwhelming sadness that twisted something inside her that wasn't there. Mavis fell down with a whimper and cried.

Slowly, as if approaching a wild animal, Zeref lowered himself next to her, draped an arm over her shoulders and let her cry, It was nice. Mavis didn't know it Zeref felt the same, if he was having second thoughts, being forced to say goodbyes to his most loyal comrades.

She didn't ask. She didn't need to know,

Once her cries ceased into sobs, she stood up.

"It's now or never, Zeref," she said, offering him her hand and a small, obviously forced smile.

Zeref looked at her hand before gripping it hard and pulling himself up. His black eyes gazed down on her green ones, and a small smile tugged at his lips. Mavis smiled back, sad.

She glanced at Fairy Heart behind them, tears in her eyes as the thought of final death came to her.

"It'll be alright, Mavis," Zeref told her. Before the few days, Mavis would have never thought that Zeref would be one to whisper comforting words to anyone. But it was sweet.

"I know," she squeezed his hand and wiped her eyes, "I know."

Zeref leaned close to her, his shoulder pressing to her and cheek coming to rest on top of her head. They gazed down on the war, saw the death, the struggling, and oddly enough, Mavis saw hope. She always liked to think that world had hope in the oddest places.

Much like this.

"Are you ready?"

Mavis shook her head. She would never be ready, not for this. If she wouldn't be desperate, she would be satisfied with how things were now. Staying there, she and Zeref, watching as their families battled against each others.

"No."

Zeref nodded. He raised his free hand, as Mavis did the same and she realized that Zeref never let go of her hand.

As Zeref chanted the words Mavis' lips and voice followed, words she refused to hear, she went over Fairy Tail's farewell ceremony inside her head.

 _"One; you must never reveal any sensitive information about Fairy Tail to others for as long as you live."_

Mavis heard that Zeref's words were struggling. She didn't blame him, she wouldn't want to say them, and maybe she wouldn't even have to. But the magic wasn't in the words. She should know that. The spell was hers, after all.

 _"Two; you must never use former contacts met through your being in the guild for personal gain."_

As they finished the final line, Mavis felt Zeref's magic spike up an shoot all around them, and she lost her thoughts. His magic embraced her in a ways it shouldn't have, caressing her skin and pressing her deeper into Zeref and to the ground she was standing on. She couldn't help but wonder, how had this man walked down the dark path?

He was, by all honesty, the gentlest man she had ever met in her life.

Before she lost the sight of the world around her, Mavis took the scenery in, then pulled at Fairy Heart for her magic, morphed it inside her and and then released it as an uncontrollable wave.

A shout came form behind them. Two shouts. Feminine, both calling her name in desperation, both voices she recognized easily.

Lucy and Cana.

Of course, she chuckled. Her two children that had more potential than anyone else but were always stomped down would be the ones to notice the change in the atmosphere before anyone else did.

Mavis leaned on Zeref's frame, enjoying the pull of her magic. She relished in the slight pain, but most of all, the felling of magic running through her in strong waves.

Lucy and Cana's shouts quietened, and Mavis wasn't sure if it was from what they saw, or that they had passed down from the pressure of their magic.

She closed her eyes. It felt good. She could hear the quiet thrum of their magic magic power.

Mavis and Zeref.

It had a nice ring to it.

The world around her did a turn. The dead, dry grass under her feet disappeared, and soon was replaced by soft soft grass under her feet. She breathed in and and smelled fresh air and nothing else. No more gunpowder, smell of blood or rotting bodies or...

"Mavis," Zeref leaned on her more heavily, swaying slightly. "Mavis."

She looked up to him, smiling as she saw that he was looking down on her, black eyes slightly closed, worried, tiredness clear on his face.

"Look around."

She did.

They were no longer looking at the battlefield. The hill was there, so was the field and the mountains in the background, but everything else told nothing of war. There was a village, a small, old looking village that was surrounded by thousands of flowers.

A picture of her and Zeref came to he mind. The two of them standing in front of a white, or possibly light blue, cute house on the edge of the village, Mavis leaning on Zeref who was standing behind her, his hands around her waist. If their story had gone differently, maybe that would have been possible.

She gripped his hand tighter, not feeling the power from Fairy Heart from behind her, meaning it had been destroyed. Then she felt it. Blood bumping in her veins, so fast it hurt. She was breathing heavily, and there was pain she hadn't felt in ages in her lungs. Her hand was sweating inside his. Her muscled ached, her head was thumping, pain.

She sucked in a deep breath. She was inside her own body.

She didn't smile. It was coming.

Mavis opened her mouth. Tried to say something, some words of thanks or apologies, maybe even words of farewell.

She didn't have the chance.

His body fell limp on the ground, the grip on her hand bringing her down with him. Mavis panicked, her free hand shot to his neck, to check his pulse. It was there, faint, but there.

"Mavis..." Zeref's voice made her focus on him, his face, his lips, his eyes. "Thank you."

Mavis pursed her lips. Her throat burned, eyes stung with tears. Her heart hammered against her rib cage with furious speed she knew was caused only by fear. When her body started trembling, Mavis knew that she still wasn't ready. Not now, not when she had found the wish to live once again. If he died and she didn't... She didn't want to think about it.

A finger on her lips, another one under her eye. She tried to focus her teary eyes oh his face. Faintly, she could see a smile caressing his lips. It was the most genuine, the most joyous smile she had ever seen him bear.

"Don't blame yourself. I'm ready for it now."

His voice was so clear, so calm and gentle and _sure_ , that Mavis for a second forgot that she was going to die too. All she was able to focus on was Zeref and his eyes and his smile and his cold fingers on her face and fading heartbeat she felt because her hand was still on his neck. She couldn't bring herself to understand why she though he was right now more beautiful than he had ever been.

Then she remembered and he wasn't beautiful anymore.

His eyes were now closed, his hand no longer on her face but on her lap where it had fallen when his pulse faded completely and the smile on his lips was no longer gentle, but only looked forced to Mavis.

A sob racked her body and the tears she had waited to fall never came.

She wanted to scream for help. For someone to come and start his heart again so that she wouldn't be alone again. Mavis leaned away from his body, looking up to the sky and closed her eyes. The pain inside her was becoming unbearable. It already hurt to breathe, her spine no longer willing to keep her body upright. She knew it was coming.

Death.

Maybe this time she could embrace it properly, and she would meet Zeref again, in the place she was going, whatever that was.

She fell on her back, a quiet cry escaping her lips as her head hit the hard ground. Blackness filled her sight even thought she knew her eyes were open. A small tug at her lips and the smile on Zeref's lips was no longer forced. It was rather comforting, allowing her body to stop functioning until her mind was the only thing that worked.

 _"Three; though our paths may have diverged, you must continue to live out your life with all your might, you must never consider your life as something insignificant, and you must never forget about the friends that loved you."_


End file.
